Java Tutorial/Hibernate/Save

Flush a Session

File: Main.java

import org.hibernate.Session;
public class Main {
  public static void main(String[] args) throws Exception {
    HibernateUtil hibernateUtil = new HibernateUtil();
    hibernateUtil.executeSQLCommand("create table survey (id int,name varchar);");
    Session session = hibernateUtil.getSession();
    Survey survey = new Survey();
    survey.setName("Survey");
    System.out.println(survey.getId());
    
    session.save(survey);
    session.flush();
    
    System.out.println(survey.getId());
    Survey surveyInSession = (Survey) session.get(Survey.class, survey.getId());
    System.out.println(surveyInSession.getName());
    session.close();
    hibernateUtil.checkData("select * from survey");
  }
}

Get Row Count With Projection

File: Main.java

import java.util.Date;
import java.util.Iterator;
import java.util.List;
import org.hibernate.Criteria;
import org.hibernate.Session;
import org.hibernate.criterion.Projections;
public class Main {
  public static void main(String[] args) throws Exception {
    HibernateUtil hibernateUtil = new HibernateUtil();
    hibernateUtil
        .executeSQLCommand("create table survey (id int,name varchar, purchasedate date);");
    Session session = hibernateUtil.getSession();
    Survey survey = new Survey();
    survey.setName("Survey");
    survey.setPurchaseDate(new Date());
    session.save(survey);
    
    survey = new Survey();
    survey.setName("Survey1");
    survey.setPurchaseDate(new Date());    
    session.save(survey);
    
    session.flush();
    
    Criteria crit = session.createCriteria(Survey.class);
    crit.setProjection(Projections.rowCount());
    
    
    List results = crit.list();
    System.out.println(results);
    
    session.close();
    hibernateUtil.checkData("select * from survey");
  }
}

Save date type data

File: Main.java

import java.util.Date;
import org.hibernate.Session;
public class Main {
  public static void main(String[] args) throws Exception {
    HibernateUtil hibernateUtil = new HibernateUtil();
    hibernateUtil.executeSQLCommand("create table survey (id int,name varchar, purchasedate date);");
    Session session = hibernateUtil.getSession();
    Survey survey = new Survey();
    survey.setName("Survey");
    survey.setPurchaseDate(new Date());
    System.out.println(survey.getId());
    
    session.save(survey);
    session.flush();
    
    System.out.println(survey.getId());
    Survey surveyInSession = (Survey) session.get(Survey.class, survey.getId());
    System.out.println(surveyInSession.getName());
    session.close();
    hibernateUtil.checkData("select * from survey");
  }
}

Save entity with Session

File: Main.java

import org.hibernate.Session;
public class Main {
  public static void main(String[] args) throws Exception {
    HibernateUtil hibernateUtil = new HibernateUtil();
    hibernateUtil.executeSQLCommand("create table survey (id int,name varchar);");
    Session session = hibernateUtil.getSession();
    Survey survey = new Survey();
    survey.setName("Survey");
    System.out.println(survey.getId());
    
    session.save(survey);
    session.flush();
    
    System.out.println(survey.getId());
    Survey surveyInSession = (Survey) session.get(Survey.class, survey.getId());
    System.out.println(surveyInSession.getName());
    session.close();
    hibernateUtil.checkData("select * from survey");
  }
}

Save linked objects twice

File: Main.java

import java.util.HashSet;
import org.hibernate.Session;
public class Main {
  public static void main(String[] args) throws Exception {
    HibernateUtil hibernateUtil = new HibernateUtil();
    hibernateUtil
        .executeSQLCommand("create table speakers (uid int, firstName varchar,lastName varchar, event_id int);");
    hibernateUtil
        .executeSQLCommand("create table locations (uid int, name varchar, address varchar,  event_id int);");
    hibernateUtil
        .executeSQLCommand("create table attendees (uid int, firstName varchar, lastName varchar,  event_id int);");
    hibernateUtil
        .executeSQLCommand("create table events (uid int , name varchar, start_date date, duration integer,location_id int);");
    Session session = hibernateUtil.getSession();
    Event e = new Event();
    e.setName("testSave");
    Location l = new Location();
    l.setName("building 1");
    e.setLocation(l);
    e.setSpeakers(new HashSet());
    e.getSpeakers().add(new Speaker("John", "Doe"));
    e.setAttendees(new HashSet());
    e.getAttendees().add(new Attendee("John", "Smith"));
    session.save(l);
    session.save(e);
    
    session.close();
    hibernateUtil.checkData("select * from events");
    hibernateUtil.checkData("select * from speakers");
    hibernateUtil.checkData("select * from locations");
    hibernateUtil.checkData("select * from attendees");
  }
}